一、原因

由于 CentOS 7 已于 2024 年 6 月 30 日 停止维护，因此官方的 yum 仓库是无法使用的，所以需要配置国内的镜像源，本文会以阿里云的镜像源操作。

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二、错误示例

[root@localhost ~]# yum update
已加载插件：fastestmirror
Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"


 One of the configured repositories failed (未知),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=<repoid> ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable <repoid>
        or
            subscription-manager repos --disable=<repoid>

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

Cannot find a valid baseurl for repo: base/7/x86_64
[root@localhost ~]# 

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三、解决方法

接下跟着下面的操作步骤就好：

（1）进入 cd /etc/yum.repos.d/ 目录

cd /etc/yum.repos.d/

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（2） 删除当前目录的所有文件

ls
rm -rf *
ls

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（3）下载新的 CentOS-Base.repo 到 /etc/yum.repos.d/ 目录

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

# 或

curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

上面的命令是针对 CentOS 7 的，如果是其他版本可以参考这个，阿里云镜像官网 。

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（4）测试是否成功

yum update

出现上面的信息代表配置成功，由于信息太长了，所以我就截了一段，注意要保证网络通畅。

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四、结语

本文于 2025 年 4 月 30 日 写的，如果后期出现配置源有问题的，可以在私信我或者评论，但是目前来看是没有什么问题的，我自己是试了几次后，才写的这篇文章。

至此，本文结束，如果这篇文章对您有所帮助，希望可以点赞、收藏加关注，感谢。

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